Validation of a sampling method and liquid chromatography mass spectrometry analysis method for measurement of fentanyl and five other illicit drugs.

With the increased provision of services by health authorities and community organizations allowing supervised inhalation of illicit substances comes concerns about the potential for secondhand exposure to the substances being used, whether in the adjacent community or to workers at the sites. In order to address community concerns surrounding secondhand illicit substance exposure and better protect harm reduction workers, a validated sampling and LC-MS/MS analysis method was developed for 6 illicit drugs: fentanyl, heroin, methamphetamine, cocaine, etizolam, and bromazolam. It was found that the filter used needed to be silanized to be made more inert and avoid loss of analyte due to degradation. Using the silanized filters, recoveries were good (>90%) and the collected samples were found to be stable at room temperature for 2 wk. The sampling volume validated was up to 960 L. The sensitivity and range of the method make it appropriate for short-term (15 min), full shift (8 h), or environmental sampling.

Clinical deterioration as a nurse sensitive indicator in the out-of-hospital context: A scoping review.

AIMS: To explore and summarise the literature on the concept of 'clinical deterioration' as a nurse-sensitive indicator of quality of care in the out-of-hospital context. DESIGN: The scoping review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Review and the JBI best practice guidelines for scoping reviews. METHODS: Studies focusing on clinical deterioration, errors of omission, nurse sensitive indicators and the quality of nursing and midwifery care for all categories of registered, enrolled, or licensed practice nurses and midwives in the out-of-hospital context were included regardless of methodology. Text and opinion papers were also considered. Study protocols were excluded. DATA SOURCES: Data bases were searched from inception to June 2022 and included CINAHL, PsychINFO, MEDLINE, The Allied and Complementary Medicine Database, EmCare, Maternity and Infant Care Database, Australian Indigenous HealthInfoNet, Informit Health and Society Database, JSTOR, Nursing and Allied Health Database, RURAL, Cochrane Library and Joanna Briggs Institute. RESULTS: Thirty-four studies were included. Workloads, education and training opportunities, access to technology, home visits, clinical assessments and use of screening tools or guidelines impacted the ability to recognise, relay information and respond to clinical deterioration in the out-of-hospital setting. CONCLUSIONS: Little is known about the work of nurses or midwives in out-of-hospital settings and their recognition, reaction to and relay of information about patient deterioration. The complex and subtle nature of non-acute deterioration creates challenges in defining and subsequently evaluating the role and impact of nurses in these settings. IMPLICATIONS FOR THE PROFESSION AND/OR PATIENT CARE: Further research is needed to clarify outcome measures and nurse contribution to the care of the deteriorating patient in the out-of-hospital setting to reduce the rate of avoidable hospitalisation and articulate the contribution of nurses and midwives to patient care. IMPACT: What Problem Did the Study Address? Factors that impact a nurse's ability to recognise, relay information and respond to clinical deterioration in the out-of-hospital setting are not examined to date. What Were the Main Findings? A range of factors were identified that impacted a nurse's ability to recognise, relay information and respond to clinical deterioration in the out-of-hospital setting including workloads, education and training opportunities, access to technology, home visits, clinical assessments, use of screening tools or guidelines, and avoidable hospitalisation. Where and on whom will the research have an impact? Nurses and nursing management will benefit from understanding the factors that act as barriers and facilitators for effective recognition of, and responding to, a deteriorating patient in the out-of-hospital setting. This in turn will impact patient survival and satisfaction. REPORTING METHOD: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Review guidelines guided this review. The PRISMA-Scr Checklist (Tricco et al., 2018) is included as (supplementary file 1).Data sharing is not applicable to this article as no new data were created or analysed in this study." NO PATIENT OR PUBLIC CONTRIBUTION: Not required as the Scoping Review used publicly available information.

The intensity and duration of occupational noise exposure and cardiovascular disease in the United States: a nationally representative study, 2015 to 2020.

OBJECTIVES: Occupational noise exposure may be associated with an increased risk of cardiovascular disease (CVD). Yet the findings are inconclusive. This study aimed to examine the association between self-reported occupational noise exposure and CVD (using a broad composite case definition and by each condition) and identify how these associations vary with the intensity and duration of noise exposure, and combinations thereof. METHODS: This cross-sectional study included a nationally representative sample (n = 6,266) from the National Health and Nutrition Examination Survey (2015 to 2020), aged 20 and greater, in the United States. Survey-weighted logistic regression models were constructed from multiple imputed datasets. RESULTS: Relative to the unexposed, the adjusted odds ratio (95% confidence interval) of composite CVD was 1.33 (1.05 to 1.67) among the noise-exposed population, and ranged from 1.23 to 1.56 when examining CVD conditions separately. The odds ratios of composite CVD were 1.43 (1.06 to 1.93), 1.43 (1.04 to 1.95), and 1.51 (1.03 to 2.21) among those who had noise exposure with very loud intensity of any duration, with duration ≥10 years at any intensity, and with a combination of very loud noise ≥10 years, respectively, compared to those unexposed. CONCLUSIONS: Increased risk of CVD is associated with occupational noise exposure, particularly at higher intensities and longer durations. Policies and interventions for noise mitigation at workplaces are warranted, targeting individuals with chronic exposure to high-level noise.

Reductions in community noise levels in vancouver, Canada, during pandemic lockdown and association with land cover type.

BACKGROUND: Urban transportation noise is a major public concern because of its adverse effects on health. The determinants of urban noise exposure have not been widely explored but the "natural experiment" presented by the COVID-19 lockdowns presented a unique opportunity. This study examined the relationship between environmental characteristics and urban noise pollution during the COVID-19 related lockdown in Metro Vancouver, Canada, from March 21st to May 18th, 2020. METHODS: We used noise exposure data from the Vancouver International Airport (YVR) noise management program, comparing the noise levels during "Phase One" of the COVID-19 lockdown in 2020 to the corresponding time period in 2019 from 21 Noise Monitoring Terminals (NMTs) located throughout Metro Vancouver. We modelled the relationship between the change in noise level and the physical NMT environments, including land cover, and total length of roads at four different time periods (24Hr, daytime, evening and nighttime) and within three different buffer zones (100 m, 250 m, and 500 m). RESULTS: Of 59,472 hourly measurements of community noise, the 24-h noise level was reduced by an average of 2.20 dBA between 2019 and 2020. Higher proportions of greenspace, barren areas, and soil-cover around NMTs resulted in stronger noise reductions and higher density of building, pavement, and water weakened the amount of noise reduction. Proximity of high-volume traffic roads (highways) were associated with weaker noise reduction. CONCLUSION: The COVID-19 related lockdown was associated with reduced noise in Metro Vancouver, and the relative reduction depended on the types of the environment surrounding the NMT. Future research on the effects of urban environmental characteristics on geographic inequality in noise levels and health consequences of the COVID-19 related lockdown is merited.

Determinants of respirable crystalline silica exposure in construction in western Canada.

Task-based respirable crystalline silica (RCS) exposure monitoring data was collected from construction work sites across 3 Canadian provinces: Alberta, British Columbia (BC), and Manitoba. In total 373 RCS samples were obtained from 70 worksites across 44 companies. Sampling was conducted between May 2015 and August 2020. The overall geometric mean (GM) RCS exposure was 0.045 mg/m3 (geometric standard deviation, GSD = 6.8). Alberta had the highest average exposure and the highest variability with GM of 0.060 mg/m3 (GSD = 9.3), the GM in BC was 0.044 (GSD = 4.3), and in Manitoba the GM was 0.033 (GSD = 7.0). A multivariable model was built using forward stepwise linear regression modeling. Province, task type, work environment (indoor vs. outdoor), construction material, sampling duration, and engineering control use were all statistically significant predictors of exposure level in partial F-tests (P < 0.05). Overall, the model explained 42% of the RCS concentration variability. Task type contributed most to the model's explanatory power. The task type with highest average exposure levels was demolition (GM 0.30 mg/m3, GSD 0.49). Breaking (GM 0.16 mg/m3, GSD 8.4) and grinding (GM 0.081 m/m3, GSD 7.4) also had high-exposure levels. Working outdoors was associated with exposure levels 39% lower than indoors. Exposure control measures such as local exhaust ventilation and wetting were also associated with lower exposure levels. Among construction materials, Cement, sand, and stone were associated with higher RCS exposure levels relative to the reference material, concrete. The results of this study indicate that workers in western Canada remain exposed to RCS at levels that exceed the health-based American Congress for Governmental Industrial Hygienists Threshold Limit Value of 0.025 mg/m3. Although there were some differences in exposure levels between the provinces, the determinants of exposure were similar in all 3. The overall GM RCS exposure was 0.045 mg/m3 (geometric standard deviation, GSD = 6.8). Alberta had the highest average exposure and the highest variability with GM of 0.060 mg/m3 (GSD = 9.3), the GM in BC was 0.044 (GSD = 4.3), and in Manitoba the GM was 0.033 (GSD = 7.0).

Psychometric properties of the Cognitive Functioning Self-Assessment Scale in community-dwelling adults: A cross-sectional online survey.

Background: The Cognitive Functioning Self-Assessment Scale (CFSS) was developed to allow the self-assessment of perceived cognitive functioning. It has been tested with satisfactory reliability and validity but was not available for the Chinese population. This study aimed to adapt and validate the Chinese version of the CFSS for community-dwelling adults. Methods: A cross-sectional study of a sample of 1,002 Chinese adults from the general population was conducted online (July-August 2022). The Chinese version of the CFSS with 18 items was created through translation, cognitive debriefing, and psychometric evaluation. Exploratory factor analysis (EFA) was performed on the first half of the randomly split sample. A model derived from EFA was confirmed by confirmatory factor analysis (CFA) in the second half of the sample. The model fits were further evaluated with and without subgrouping by age, gender, and education level. Internal consistency was assessed using Cronbach's alpha (α) and McDonald's omega hierarchical coefficients (ωH). Results: EFA (n = 460) revealed a three-factor solution, including spatio-temporal orientation, attention, and memory, which explained 51% of the total variance. The second-order CFA (n = 510) demonstrated a good fit: CFI = 0.951, TLI = 0.944, RMSEA = 0.054, SRMR = 0.040. A second-order multiple-group analysis showed that the structure was invariant by age, gender, and education level. The total CFSS score was significantly associated with the Chinese version of the nine-item Patient Health Questionnaire (r = 0.56, p< 0.001) and the Chinese version of the seven-item General Anxiety Disorder (r = 0.53, p<0.001). The internal consistency reliability was satisfactory, with α = 0.94 and ωH = 0.84. The item-total correlation coefficients ranged from 0.58 to 0.72. Conclusion: The Chinese version of the CFSS possesses good item characteristics, satisfactory validity, and reliability for assessing self-reported cognitive functioning among community-dwelling adults. It is a feasible and appropriate self-assessment instrument to examine cognitive functioning in the Hong Kong Chinese population, which contributes to monitoring and developing strategies to prevent and manage cognitive impairment and disorders for the public's cognitive health and well-being.

Population genomics and conservation management of the threatened black-footed tree-rat (Mesembriomys gouldii) in northern Australia.

Genomic diversity is a fundamental component of Earth's total biodiversity, and requires explicit consideration in efforts to conserve biodiversity. To conserve genomic diversity, it is necessary to measure its spatial distribution, and quantify the contribution that any intraspecific evolutionary lineages make to overall genomic diversity. Here, we describe the range-wide population genomic structure of a threatened Australian rodent, the black-footed tree-rat (Mesembriomys gouldii), aiming to provide insight into the timing and extent of population declines across a large region with a dearth of long-term monitoring data. By estimating recent trajectories in effective population sizes at four localities, we confirm widespread population decline across the species' range, but find that the population in the peri-urban area of the Darwin region has been more stable. Based on current sampling, the Melville Island population made the greatest contribution to overall allelic richness of the species, and the prioritisation analysis suggested that conservation of the Darwin and Cobourg Peninsula populations would be the most cost-effective scenario to retain more than 90% of all alleles. Our results broadly confirm current sub-specific taxonomy, and provide crucial data on the spatial distribution of genomic diversity to help prioritise limited conservation resources. Along with additional sampling and genomic analysis from the far eastern and western edges of the black-footed tree-rat distribution, we suggest a range of conservation and research priorities that could help improve black-footed tree-rat population trajectories at large and fine spatial scales, including the retention and expansion of structurally complex habitat patches.

UK Research Ethics Committee's review of the global first SARS-CoV-2 human infection challenge studies.

This paper describes the UK Research Ethics Committee's (REC) preparations and review of the global first SARS-CoV-2 human infection challenge studies. To frame our review, we used the WHO guidance and our UK Health Research Authority ethical review framework. The WHO criteria covered most issues we were concerned about, but we would recommend one further criterion directing RECs to consider alternative research designs. Could research questions be equally well answered by less intrusive studies? The committee met virtually, ensuring broad representation across the UK nations and also ensuring applicants could attend easily. We worked in collaboration with the applicants but while we recognise that such proximity might raise the accusation of 'collusion', we made every effort to maintain 'moral distance' and all decisions were made by the committee alone. Prior existing processes and policy facilitated training and review but even with this preparation, review took time and this could have hindered a rapid response to the emergency. Review for the various follow-on studies will now be speedier and once the pandemic has subsided, our group could be reconvened in future emergencies. In conclusion, we have tried to make decisions in good faith. We know there is controversy and disagreement and reasonable people may feel we have made the wrong decision. A more detailed analysis, built on the WHO guidance, is provided in online supplemental material.

Developing wipe sampling strategy guidance for assessing environmental contamination of antineoplastic drugs.

Surveillance for environmental contamination of antineoplastic drugs has been recommended by authoritative bodies such as the United States Pharmacopeia and the National Association of Pharmacy Regulatory Authorities. Clear guidance is needed on how to develop sampling strategies that align with surveillance objectives efficiently and effectively. We conducted a series of simulations using previously collected surveillance data from nine cancer treatment centers to evaluate different sampling strategies. We evaluated the impact of sampling 2, 5, 10, or 20 surfaces, at monthly, quarterly, semi-annual, and annual frequencies, while employing either a random or sentinel surface selection strategy to assess contamination by a single antineoplastic drug (AD) or by a panel of three ADs. We applied two different benchmarks: a binary benchmark of above or below the limit of detection and AD-specific hygienic guidance values, based on 90th percentile values as quantitative benchmarks. The use of sentinel surfaces to evaluate a three-drug panel relative to 90th percentile hygienic guidance values (HGVs) resulted in the most efficient and effective surveillance strategy.

Impact of pre-registration extended immersive ward-based simulation on student learning in preparation for clinical placement.

BACKGROUND: Graduate nurses commonly experience significant challenges in transitioning to professional practice. The practice readiness of graduate nurses continues to be a concern for nurse educators and industry partners. Introduction of pre-registration extended immersive ward-based simulation can provide opportunities for students to practice the role of registered nurse before graduation. It is not clear if participation in simulation-based learning transfers to increased preparedness for dealing with real-life situations following entry into the workforce. OBJECTIVE: To report on student views on how ward-based immersive simulation assisted in preparing for clinical placement and graduate practice. DESIGN: A qualitative, descriptive design was used to conduct a series of face-to-face focus groups. SETTING: School of Nursing and Midwifery metropolitan Western Australian university. PARTICIPANTS: Final year baccalaureate nursing students who had participated in six four-hour simulation workshops between February and April 2021 were selected through purposive sampling. METHODS: Focus group and interview data was transcribed from audio recordings. A six-phase approach was used to analyse data into themes and sub-themes. The study adhered to the consolidated criteria for reporting of qualitative research. RESULTS: Three focus groups and one interview were conducted. Eight themes emerged. Student learning was identified as occurring in a variety of ways, such as how to work as a team and was influenced by a number of factors, such as the capacity for students to self-reflect. CONCLUSIONS: Learning opportunities for students to practice how to think and work independently as a registered nurse is something that can be supported by pre-registration extended immersive ward-based simulation. Understanding of what will be expected of them once qualified can make students more prepared for professional practice enabling them to apply knowledge gained from simulated experiences to a similar situation as a graduate nurse.

Ethical Considerations for the Inclusion of Patient-Reported Outcomes in Clinical Research: The PRO Ethics Guidelines.

Importance: Patient-reported outcomes (PROs) can inform health care decisions, regulatory decisions, and health care policy. They also can be used for audit/benchmarking and monitoring symptoms to provide timely care tailored to individual needs. However, several ethical issues have been raised in relation to PRO use. Objective: To develop international, consensus-based, PRO-specific ethical guidelines for clinical research. Evidence Review: The PRO ethics guidelines were developed following the Enhancing the Quality and Transparency of Health Research (EQUATOR) Network's guideline development framework. This included a systematic review of the ethical implications of PROs in clinical research. The databases MEDLINE (Ovid), Embase, AMED, and CINAHL were searched from inception until March 2020. The keywords patient reported outcome* and ethic* were used to search the databases. Two reviewers independently conducted title and abstract screening before full-text screening to determine eligibility. The review was supplemented by the SPIRIT-PRO Extension recommendations for trial protocol. Subsequently, a 2-round international Delphi process (n = 96 participants; May and August 2021) and a consensus meeting (n = 25 international participants; October 2021) were held. Prior to voting, consensus meeting participants were provided with a summary of the Delphi process results and information on whether the items aligned with existing ethical guidance. Findings: Twenty-three items were considered in the first round of the Delphi process: 6 relevant candidate items from the systematic review and 17 additional items drawn from the SPIRIT-PRO Extension. Ninety-six international participants voted on the relevant importance of each item for inclusion in ethical guidelines and 12 additional items were recommended for inclusion in round 2 of the Delphi (35 items in total). Fourteen items were recommended for inclusion at the consensus meeting (n = 25 participants). The final wording of the PRO ethical guidelines was agreed on by consensus meeting participants with input from 6 additional individuals. Included items focused on PRO-specific ethical issues relating to research rationale, objectives, eligibility requirements, PRO concepts and domains, PRO assessment schedules, sample size, PRO data monitoring, barriers to PRO completion, participant acceptability and burden, administration of PRO questionnaires for participants who are unable to self-report PRO data, input on PRO strategy by patient partners or members of the public, avoiding missing data, and dissemination plans. Conclusions and Relevance: The PRO ethics guidelines provide recommendations for ethical issues that should be addressed in PRO clinical research. Addressing ethical issues of PRO clinical research has the potential to ensure high-quality PRO data while minimizing participant risk, burden, and harm and protecting participant and researcher welfare.

The influence of early-life residential exposure to different vegetation types and paved surfaces on early childhood development: A population-based birth cohort study.

BACKGROUND: Growing evidence suggests that exposure to green space is associated with improved childhood health and development, but the influence of different green space types remains relatively unexplored. In the present study, we investigated the association between early-life residential exposure to vegetation and early childhood development and evaluated whether associations differed according to land cover types, including paved land. METHODS: Early childhood development was assessed via kindergarten teacher-ratings on the Early Development Instrument (EDI) in a large population-based birth cohort (n = 27,539) in Metro Vancouver, Canada. The residential surrounding environment was characterized using a high spatial resolution land cover map that was linked to children by six-digit residential postal codes. Early-life residential exposure (from birth to time of EDI assessment, mean age = 5.6 years) was calculated as the mean of annual percentage values of different land cover classes (i.e., total vegetation, tree cover, grass cover, paved surfaces) within a 250 m buffer zone of postal code centroids. Multilevel models were used to analyze associations between respective land cover classes and early childhood development. RESULTS: In adjusted models, one interquartile range increase in total vegetation percentage was associated with a 0.33 increase in total EDI score (95% CI: 0.21, 0.45). Similar positive associations were observed for tree cover (ß-coefficient: 0.26, 95% CI: 0.15, 0.37) and grass cover (ß-coefficient: 0.12, 95% CI: 0.02, 0.22), while negative associations were observed for paved surfaces (ß-coefficient: -0.35, 95% CI: -0.47, -0.23). CONCLUSIONS: Our findings indicate that increased early-life residential exposure to vegetation is positively associated with early childhood developmental outcomes, and that associations may be stronger for residential exposure to tree cover relative to grass cover. Our results further indicate that childhood development may be negatively associated with residential exposure to paved surfaces. These findings can inform urban planning to support early childhood developmental health.

Ethics review of COVID-19 human challenge studies: A joint HRA/WHO workshop.

This report of a joint World Health Organization (WHO) and United Kingdom (UK) Health Research Authority (HRA) workshop discusses the ethics review of the first COVID-19 human challenge studies, undertaken in the midst of the pandemic. It reviews the early efforts of international and national institutions to define the ethical standards required for COVID-19 human challenge studies and create the frameworks to ensure rigorous and timely review of these studies. This report evaluates the utility of the WHO's international guidance document Key criteria for the ethical acceptability of COVID-19 human challenge studies (WHO Key Criteria) as a practical resource for the ethics review of COVID-19 human challenge studies. It also assesses the UK HRA's approach to these complex ethics reviews, including the formation of a Specialist Ad-Hoc Research Ethics Committee (REC) for COVID-19 Human Challenge Studies to review all current and future COVID-19 human challenge studies. In addition, the report outlines the reflections of REC members and researchers regarding the ethics review process of the first COVID-19 human challenge studies. Finally, it considers the potential ongoing scientific justification for COVID-19 human challenge studies, particularly in relation to next-generation vaccines and optimisation of vaccination schedules. Overall, there was broad agreement that the WHO Key Criteria represented an international consensus document that played a powerful role in setting norms and delineating the necessary conditions for the ethical acceptability of COVID-19 human challenge studies. Workshop members suggested that the WHO Key Criteria could be practically implemented to support researchers and ethics reviewers, including in the training of ethics committee members. In future, a wider audience may be engaged by the original document and potential additional materials, informed by the experiences of those involved in the first COVID-19 human challenge studies outlined in this document.

Neighborhood environmental exposures and incidence of attention deficit/hyperactivity disorder: A population-based cohort study.

BACKGROUND: Emerging studies have associated low greenspace and high air pollution exposure with risk of child attention deficit/hyperactivity disorder (ADHD). Population-based studies are limited, however, and joint effects are rarely evaluated. We investigated associations of ADHD incidence with greenspace, air pollution, and noise in a population-based birth cohort. METHODS: We assembled a cohort from administrative data of births from 2000 to 2001 (N âˆ¼ 37,000) in Metro Vancouver, Canada. ADHD was identified by hospital records, physician visits, and prescriptions. Cox proportional hazards models were applied to assess associations between environmental exposures and ADHD incidence adjusting for available covariates. Greenspace was estimated using vegetation percentage derived from linear spectral unmixing of Landsat imagery. Fine particulate matter (PM2.5) and nitrogen dioxide (NO2) were estimated using land use regression models; noise was estimated using a deterministic model. Exposure period was from birth until the age of three. Joint effects of greenspace and PM2.5 were analysed in two-exposure models and by categorizing values into quintiles. RESULTS: During seven-year follow-up, 1217 ADHD cases were diagnosed. Greenspace was associated with lower incidence of ADHD (hazard ratio, HR: 0.90 [0.81-0.99] per interquartile range increment), while PM2.5 was associated with increased incidence (HR: 1.11 [1.06-1.17] per interquartile range increment). NO2 (HR: 1.01 [0.96, 1.07]) and noise (HR: 1.00 [0.95, 1.05]) were not associated with ADHD. There was a 50% decrease in the HR for ADHD in locations with the lowest PM2.5 and highest greenspace exposure, compared to a 62% increase in HR in locations with the highest PM2.5 and lowest greenspace exposure. Effects of PM2.5 were attenuated by greenspace in two-exposure models. CONCLUSIONS: We found evidence suggesting environmental inequalities where children living in greener neighborhoods with low air pollution had substantially lower risk of ADHD compared to those with higher air pollution and lower greenspace exposure.

Diesel Engine Exhaust Exposure in the Ontario Civil Infrastructure Construction Industry.

OBJECTIVES: Diesel engine exhaust (DEE) is a known lung carcinogen and a common occupational exposure in Canada. The use of diesel-powered equipment in the construction industry is particularly widespread, but little is known about DEE exposures in this work setting. The objective of this study was to determine exposure levels and identify and characterize key determinants of DEE exposure at construction sites in Ontario. METHODS: Elemental carbon (EC, a surrogate of DEE exposure) measurements were collected at seven civil infrastructure construction worksites and one trades training facility in Ontario using NIOSH method 5040. Full-shift personal air samples were collected using a constant-flow pump and SKC aluminium cyclone with quartz fibre filters in a 37-mm cassette. Exposures were compared with published health-based limits, including the Dutch Expert Committee on Occupational Safety (DECOS) limit (1.03 µg m-3 respirable EC) and the Finnish Institute of Occupational Health (FIOH) recommendation (5 µg m-3 respirable EC). Mixed-effects linear regression was used to identify determinants of EC exposure. RESULTS: In total, 149 EC samples were collected, ranging from <0.25 to 52.58 µg m-3 with a geometric mean (GM) of 3.71 µg m-3 [geometric standard deviation (GSD) = 3.32]. Overall, 41.6% of samples exceeded the FIOH limit, mostly within underground worksites (93.5%), and 90.6% exceeded the DECOS limit. Underground workers (GM = 13.20 µg m-3, GSD = 1.83) had exposures approximately four times higher than below grade workers (GM = 3.56 µg m-3, GSD = 1.94) and nine times higher than above ground workers (GM = 1.49 µg m-3, GSD = 1.75). Training facility exposures were similar to above ground workers (GM = 1.86 µg m-3, GSD = 4.12); however, exposures were highly variable. Work setting and enclosed cabins were identified as the key determinants of exposure in the final model (adjusted R2 = 0.72, P < 0.001). The highest DEE exposures were observed in underground workplaces and when using unenclosed cabins. CONCLUSIONS: This study provides data on current DEE exposure in Canadian construction workers. Most exposures were above recommended health-based limits, albeit in other jurisdictions, signifying a need to further reduce DEE levels in construction. These results can inform a hazard reduction strategy including targeted intervention/control measures to reduce DEE exposure and the burden of occupational lung cancer.

Exposure to Whole-Body Vibration in Commercial Heavy-Truck Driving in On- and Off-Road Conditions: Effect of Seat Choice.

Trucking is a key industry in Canada with around 180 000 professional drivers. As an industry it has a disproportionately high injury claim rate, particularly for back injuries. Whole-body vibration (WBV) can contribute to the onset and development of low back disorders, and is a well-documented exposure among driving professions. A widely adopted WBV mitigation measure focuses on hydraulic and/or pneumatic passive suspension systems both in the driver's seat and underneath the vehicle cab. Passive suspension 'air-ride' seats are the current industry standard but new technologies such as the electromagnetic active vibration cancelling (EAVC) seats offer potentially substantial improvements in WBV reduction. In this paper, we evaluate and compare four commonly used truck seats (three air-ride, one EAVC) for their vibration damping characteristics and WBV exposure attenuation in on- and off-road conditions. We recruited 24 professional truck drivers who drove 280 km (mixed on-road and off-road) in ore-haul trucks under four different seating conditions. Following the ISO 2631-1 WBV standard, vibration measurements were made on the cab floor and seat pad, and 8-h average weighted vibration (A(8)) and 8-h vibration dose values (VDV(8)) were calculated, as well as the Seat Effective Amplitude Transmissibility (SEAT), and daily vibration action limits (DVALs). These measures were compared between seat types, as well as road conditions. The EAVC seat gave best performance for both A(8) (0.27 m s-2) and VDV(8) (6.6 m s-1.75). The EVAC seat had the lowest SEAT tested (36.2%) and the longest DVAL. However, among the three passive air-suspension seats, two showed significantly reduced A(8) (0.43 and 0.44 m s-2) and VDV(8) (9.1 and 9.3 m s-1.75) exposures relative to the third passive air-suspension seats [A(8) (0.54 m s-2) and VDV(8) (11.1 m s-1.75)]. These differences in exposures among the three passive air-suspension seats resulted in varying DVAL times, with the worst performing seat reaching the DVAL after only 6.3 h of driving. There was also a seat by road type interaction; there were performance differences between the passive air-suspension seats on-road, but not off-road. The observed reduction of the WBV exposures measured from the EAVC seat was consistent with previous results. But we showed that there can also be substantive differences among seats that are the current industry standard. These differences were more evident on-road than off-road, which suggests that more work needs to be done to understand seat performance characteristics, and in matching the correct seat technology to the driving task. We demonstrated that WBV exposures in current industry conditions may exceed health-based exposure limits; this has policy relevance because WBV exposures are linked to prevalent and costly adverse health conditions in a working population that is ageing. Increased WBV measurement collection is recommended to ensure the anticipated exposure attenuations are achieved when seats are relied upon as an engineered control against WBV.

Break-even Analysis of Respirable Crystalline Silica (RCS) Exposure Interventions in the Construction Sector.

OBJECTIVE: We investigated long-term economic impacts of respirable crystalline silica (RCS) removal interventions in the construction at the societal level. METHODS: We estimated costs and benefits of two RCS exposure interventions, use of "respirators" and "wet method," over a 30-year time period. We identified economic impacts of the interventions under four different scenarios. RESULTS: Under current practices, we estimated that approximately 125 lung cancer cases attributable to RCS exposure would arise in 2060. Under the full exposure removal scenario, we estimated there would be 53 new cases. Over the 30-year time period, the estimated cumulative averted cases are 787 and 482 for respirators and wet method, respectively, which amount to net benefits of $422.13 and $394.92 million. CONCLUSIONS: Findings provide important information for policymakers seeking to reduce the economic burden of occupational lung cancer in society.